Eble JN, Sauter G., Epstein JI, Sesterhenn IA - iarc

Melanocytic lesions
A.G. Ayala
P. Tamboli
Definition
Melanocytic lesions of the penis identical
to those in other sites.
Incidence
Malignant melanocytic lesions of the
penis are rare, with just over 100 cases
of malignant melanoma reported since
their first description by Muchison in
1859 {1229,1439,1614,1950}. Other melanocytic
lesions include penile
melanosis, genital lentiginosis, atypical
lentiginous hyperplasia, melanocytic
nevi, and atypical melanocytic nevi of the
acral/genital type.
ICD-O codes
Melanocytic nevi 8720/0
Melanoma 8720/3
Fig. 5.25 Invasive melanoma. Perspective view of the atypical junctional component.
Epidemiology and etiology
Penile melanoma affects white men,
between the ages of 50 and 70 years.
Risk factors include pre-existing nevi,
exposure to ultraviolet radiation, and a
history of melanoma.
Localization
Sixty to eighty percent of melanomas
arise on the glans penis, less than 10%
affect the prepuce, and the remainder
arises from the skin of the shaft.
Macroscopy
Grossly, the lesion has been described
as an ulcer, papule, or nodule that is
blue, brown, or red.
A
Fig. 5.26 Melanoma in situ. A In this illustration there are scattered large atypical melanocytes involving all
layers of the epithelium. B This lesion shows an atypical junctional melanocytic proliferation associated
with melanocytic cells that are present in the upper layers of the epithelium. Although the low power suggests
a dysplastic nevus, the presence of atypical melanocytes migrating to different levels of the epithelium
makes it a melanoma in situ.
B
Histopathology
Reported histologic subtypes include
nodular, superficial spreading, and
mucosal lentiginous. The Breslow level
(depth of invasion) is an important determinant
of overall survival.
Prognosis and predictive factors
Management is similar to melanomas of
other regions.
Melanocytic lesions 291